Brokendown......If I were you, I definitely would not go! Why put yourself through that?
I would just tell him that y ou have better things to do than go on a floating drink fest.
If he doesn't like it...I would just tell him that you hope he feels better in the future.
You could always ask him to respect th e holiday and keep the drinking in check.....
Of course, he might get surly and resentful toward you....So, I say to just weigh out which is the worst consequence....
Surly with resentment ...or, hung over.......!